EXPR(1)

📦
version 9.12 · 26 versions
, in arch rolling

✨ EXPR(1) — the expr glow-up ✨

okay bestie, sit down, we're learning expr 💅 it lives in User Commands land and it literally just... evaluates expressions. that's the whole vibe.

🌸 NAME 🌸

expr — evaluate expressions 🧮✨

🎀 SYNOPSIS 🎀

expr EXPRESSION
expr OPTION

💖 DESCRIPTION 💖

  • --help — display this help and exit 🥰
  • --version — output version information and exit 👑

then it prints the value of EXPRESSION to standard output. the blank line below separates the increasing-precedence groups (so like, the stuff lower down binds tighter, iykyk). EXPRESSION may be:

  • ARG1 | ARG2 — gives you ARG1 if it's neither null nor 0, otherwise ARG2 🦋
  • ARG1 & ARG2 — gives you ARG1 if neither argument is null or 0, otherwise 0 💀
  • ARG1 < ARG2 — ARG1 is less than ARG2
  • ARG1 <= ARG2 — ARG1 is less than or equal to ARG2
  • ARG1 = ARG2 — ARG1 is equal to ARG2
  • ARG1 != ARG2 — ARG1 is unequal to ARG2
  • ARG1 >= ARG2 — ARG1 is greater than or equal to ARG2
  • ARG1 > ARG2 — ARG1 is greater than ARG2
  • ARG1 + ARG2 — arithmetic sum of ARG1 and ARG2 ➕
  • ARG1 - ARG2 — arithmetic difference of ARG1 and ARG2 ➖
  • ARG1 * ARG2 — arithmetic product of ARG1 and ARG2 ✖️
  • ARG1 / ARG2 — arithmetic quotient of ARG1 divided by ARG2 ➗
  • ARG1 % ARG2 — arithmetic remainder of ARG1 divided by ARG2 🍓
  • STRING : REGEXP — anchored pattern match of REGEXP in STRING 🔍
  • match STRING REGEXP — same as STRING : REGEXP fr fr
  • substr STRING POS LENGTH — substring of STRING, POS counted from 1 ✂️
  • index STRING CHARS — index in STRING where any CHARS is found, or 0 🧭
  • length STRING — length of STRING 📏
  • + TOKEN — interpret TOKEN as a string, even if it is a keyword like 'match' or an operator like '/' 🙈 (this one is the sneaky icon tbh)
  • ( EXPRESSION ) — value of EXPRESSION 🫶
⚠️ bestie beware: many operators need to be escaped or quoted for shells. no cap. if you forget, your shell will eat your operators and you'll be sad 😭

comparisons are arithmetic if both ARGs are numbers, else lexicographical. pattern matches return the string matched between \( and \) or null; if \( and \) are not used, they return the number of characters matched or 0. 💅

exit status is 0 if EXPRESSION is neither null nor 0, 1 if EXPRESSION is null or 0, 2 if EXPRESSION is syntactically invalid, and 3 if an error occurred. so basically 0 = slay, 1 = falsy vibes, 2 = syntax said no, 3 = something actually broke 🌈

👑 AUTHOR 👑

Written by Mike Parker, James Youngman, and Paul Eggert. legends, honestly 🫡✨

🐛 REPORTING BUGS 🐛

Report bugs to: <bug-coreutils@gnu.org>. Report any translation bugs to: <https://translationproject.org/team/>. GNU coreutils home page: <https://www.gnu.org/software/coreutils/> General help using GNU software: <https://www.gnu.org/gethelp/>

like pls tell them, they wanna know 💜

Copyright © 2026 Free Software Foundation, Inc. License GPLv3+: GNU GPL version 3 or later <https://gnu.org/licenses/gpl.html>. This is free software: you are free to change and redistribute it. There is NO WARRANTY, to the extent permitted by law.

🚨 there is NO WARRANTY bestie. none. zero. read it again, to the extent permitted by law.

🌈 SEE ALSO 🌈

Full documentation <https://www.gnu.org/software/coreutils/expr> or available locally via: info '(coreutils) expr invocation'

and that's the whole page, main character energy only ✨ this was GNU coreutils 9.12, dated September 2026 — go forth and expr responsibly, bestie 💖🎀🦋

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